Over the past nine years I’ve spent over a year at sea, counting seabirds in the Atlantic and Arctic Oceans from the bridge of large Canadian Coast Guard vessels. There is a clearly defined protocol that is followed: I focus on the birds on one side of the ship (usually the port side) and try to place them in terms of distance from the ship within a moving 300 square meter area. The area is moving because….the ship is. Ideally each bird (or birds) is identified; counted; sorted as to whether it is sitting on the water or flying; and then placed in a distance category relative to the ship: 0-50 m, 50-100 m, 100-200m, 200-300 m, and >300 m. Birds on the opposite side of the vessel may be noted and recorded but they don’t figure into the calculation of bird density; i.e., number of birds per square kilometer which this methodology strives to achieve. Birds are counted in 5-minute “batches” or “watches” which are continuously renewed as the count progresses.
The recording of each record is done using Dragon – voice recognition software – which populates a database as you speak. To make things easier, instead of writing out the long form of a bird’s name, only the 4-letter alpha code is entered. Those familiar with banding will recognize this right away as we use the same method for recording the birds we band. Disregarding exceptions (and there are many!), it works like this: you take the first 2 letters of the first name and the first 2 letters of the second name and, presto!, you have the alpha code. So….let’s practice: Song Sparrow? SOng SParrow = SOSP. Northern Gannet? NOrthern GAnnet = NOGA. Simple right? In most instances this works but you have to learn the outliers separately: e.g., Black-throated Green Warbler is BTNW so you don’t confuse it with Black-throated Gray Warbler, which, of course, is BTYW. Simple…right?
So let me get back to the gist of this post. Usually I don’t see many landbirds when I’m out on the ocean unless I’m travelling during migration periods (my last two blogs were about this). Now, when a landbird goes by you don’t have a lot of time to make a discrimination; the bird is moving at speed and the ship is moving at speed (as well as up and down and sideways at times) and if they’re moving in opposite directions then they’re moving at great speed. Further, you can’t wait for the bird to land in a convenient tree or bush so you can sneak up and make an ID. Unless that bird lands on the ship, on the forward deck, you’re going to have a hard time. Because the other reason is that….you’re not really looking for them. Your concentration is on the sea out in front and to the side, usually at quite a distance. And then suddenly this little feathered blob whips into your peripheral vision moving at speed and by the time you can get your binocs positioned and refocused it’s gone. And, although you’d dearly like to make an identification, you hope that it doesn’t land on the ship or, if it does, it doesn’t settle in. Too many never leave it alive – it’s a death trap the longer they stay. There’s little to no food and eventually they simply run out of energy and die of hypothermia.
So how do you account for these travellers in the database? If you can’t make an ID they are recorded simply as UNPAs – Unidentified Passerine. I had a few of these today – and I think they had happy endings! We were steaming from the west end of the Strait of Belle Isle (separating Newfoundland from Quebec/Labrador) to the north side of Anticosti Island across a big empty stretch of the Gulf of St. Lawrence. Suddenly, from the corner of my eye, I notice a little group of 5 songbirds winging their way WSW parallel to the ship, which was headed the same way. Only these birds were moving faster than we were and by the time I got my binocs in position all I got was the tail ends – they were sparrow/myrtle warbler size…..UNPAs as I couldn’t be sure.
So, what about that happy ending? First of all, they did NOT land on the ship. They kept going and I watched them through my binoculars until they disappeared in the distance. But there was a lot of water in front of us at this point: about 100 nautical miles to the east end of Anticosti. A nautical mile is about 1.85 kilometers so they had about 185 kilometers to go. The ship was travelling 13.5 knots or nautical miles per hour. The birds easily passed us so let’s say they were going at least 18 knots. Using the conversion above, that works out to 33 kilometers per hour. At that rate they should be able to get there in about 5.6 hours, which is pretty comfortable for these birds if they’re carrying energy in the form of fat. But they had something else going for them: shortly after they passed me the wind began to pick up blowing from the ENE directly toward Anticosti Island. Within 2 hours it went from 4 knots to 17 knots (7 kilometers per hour to 33 kilometers per hour). This assisting wind would likely have cut the travel time by about half!
So, unless a jaeger or a peregrine falcon came along, it’s quite conceivable that these UNPAs spent most of the day foraging on Anticosti Island, resting and building up fat for the next leg – the jump to the mainland.
[For possible predators I used jaegers and peregrine falcons as examples because I have seen them take small birds well out at sea. Jaegers I have witnessed catch Snow Buntings on their passage from Greenland to Baffin Island across the Davis Strait and a Peregrine I’ve seen take a phalarope 90 miles off the coast of northern Labrador – and begin plucking it as it flew.]